I suppose it is useless to undertake to reform men of one idea. The real trouble is that the pebble is in them; and whole freshets of truth are poured upon them, only with the effect to make it more lively in its grinding, and more certain in its process of wearing out itself and them. The little man who, when ordered by his physician to take a quart of medicine, informed him with a deprecatory whimper, that he did not hold but a pint, illustrates the capacity of many of those who are subjects of a single idea. They do not hold but one, and it would be useless to prescribe a larger number. In a country like ours, in which every thing is new and everybody is free, there are multitudes of self-constituted doctors, each of whom has a nostrum for curing all physical and moral disorders and diseases,--a patent process by which humanity may achieve its proudest progress and its everlasting happiness. The country is full of hobby-riders, booted and spurred, who imagine they are leading a grand race to a golden goal, forgetful of the truth that their steeds are tethered to a single idea, around which they are revolving only to tread down the grass and wind themselves up, where they may stand at last amid the world's ridicule, and starve to death. Man cannot live by bread alone, but by every word that proceeds out of the mouth of God, whether spoken through nature or revelation. There is no one idea in all God's universe so great and so nutritious that it can furnish food for an immortal soul. Variety of nutriment is absolutely essential, even to physical health. There are so many elements that enter into the structure of the human body, and such variety of stimuli requisite for the play of its vital forces, that it is necessary to lay under tribute a wide range of nature; and fruits and roots and grain, beasts of the field, fowls of the air, and fish of the sea, juices and spices and flavors, all bring their contributions to the perfection of the human animal, and the harmony of its functions. The sailor, kept too long upon his hard biscuit and salt junk, degenerates into scurvy. The occupant of the Irish hovel who lives upon his favorite root, and sees neither bread nor meat, grows up with weak eyes, an ugly face, and a stunted body. It is precisely thus with a man who occupies and feeds his mind with a single idea. He grows mean and small and diseased with the diet. The soul bears relation to such a wealth of truth, such a multitude of interests cluster about it, it has such variety of elements--as illustrated by its illimitable range of action and passion--it touches and receives impressions from all other souls at such an infinite variety of points, that it is simply absurd to suppose that one idea can feed it, even for a day.